Lerdahl and Jackendoff's Generative Theory of Tonal Music (GTTM) is an important contribution to cognitive science. Jackendoff claims it is a computationalist theory and that the mental representations it postulates are unconscious. Thus GTTM looks to be a kind of cognitive science remote from the folk-psychological. I argue that this picture of GTTM is mistaken: GTTM is at least as much music analysis as cognitive science. Jackendoff's metatheory fails to explain how a listener can tell that a structural description corresponds to the way she hears, how analytically minded listeners can communicate about their hearing, and how a reader of their book can comprehend it. I suggest an alternative construal, on which GTTM's analytical vocabulary functions as a public language and its mental representations are perceptual beliefs. Interesting philosophical problems ensue about knowledge of musical structure and knowledge about what structures one hears. There is a paradox: one wants an analysis to be true to a hearing, yet to be illuminating. Though analysis and hearing coincide in content at an abstract level, they do not coincide in conceptual content. What sort of knowledge then underlies the inference from perceptual to music-analytical representation? I argue that such knowledge is a priori.